ExxonMobil predicts diesel will overtake gasoline as the most popular fuel used in transportation by 2020.

ExxonMobil predicts diesel will overtake gasoline as the most popular fuel used in transportation by 2020.

One of the main reasons is related to a significant boost in global commercial transportation and also thanks to an increase in light-duty engine efficiency. In the "Outlook For Energy: A View to 2040" report, ExxonMobil predicts diesel will represent about 70 percent of all growth in demand for transportation fuel through 2040.

Demand for gasoline will remain just about the same in the next several decades, but over the next 27 years demand for diesel-powered heavy-duty vehicles will increase by 65 percent. Developing countries are expected to have an 80 percent surge in commercial transportation in the meantime.

As far as hybrids are concerned, ExxonMobil believes these cars will be more affordable by 2025 so their popularity should start increasing around that period. By 2040, global vehicle fleet will consist of 40 percent full hybrids, while plug-in hybrids and EVs will represent only 5 percent of the market by then.